seeed studio Grove-125KHz RFID Reader User manual

Grove - 125KHz RFID Reader
This Grove-125KHz RFID Reader is a module used to read uem4100 RFID card
information with two output formats: Uart and Wiegand. It has a sensitivity with
maximum 7cm sensing distance. There is also the electronic brick version of this
module. It can help you with project like internet of thing and access control system.
Version
Product Version Changes Released Date
Grove - 125KHz RFID Reader V1.0 Initial Oct 2015
Specifications
Parameter Value/Range
Voltage 4.75-5.25V
Working Frequency 125 KHz
Sensing
Distance(Max)
70mm
TTL Output 9600 baudrate, 8 data bits, 1 stop bit, and no verify bit
Wiegand Output 26 bits Wiegand format, 1 even verify bit, 24 data bits, and 1 odd
verify bit
Tip
More details about Grove modules please refer to Grove System
Platforms Supported
Arduino Raspberry Pi

Arduino Raspberry Pi
Caution
The platforms mentioned above as supported is/are an indication of the module's
software or theoritical compatibility. We only provide software library or code examples
for Arduino platform in most cases. It is not possible to provide software library / demo
code for all possible MCU platforms. Hence, users have to write their own software
library.
Getting Started
Note
If this is the first time you work with Arduino, we firmly recommend you to see Getting
Started with Arduino before the start.
Play With Arduino
Hardware
 Step 1. Prepare the below stuffs:
Seeeduino V4.2 Base Shield Grove - 125KHz RFID Reader
Get One Now Get One Now Get One Now
 Step 2. Connect Grove - 125KHz RFID Reader to port D2 of Grove-Base
Shield.
 Step 3. Plug Grove - Base Shield into Seeeduino.

 Step 4. Connect Seeeduino to PC via a USB cable.
Note
If we don't have Grove Base Shield, We also can directly connect
Grove_Ultrasonic_Ranger to Seeeduino as below.
Seeeduino Grove - 125KHz RFID Reader
5V Red
GND Black
D3 White
D2 Yellow
Software
 Step 1. Copy the code into Arduino IDE and upload. If you do not know how
to upload the code, please check how to upload code.
/*
link between the computer and the SoftSerial Shield
at 9600 bps 8-N-1
Computer is connected to Hardware UART

SoftSerial Shield is connected to the Software UART:D2&D3
*/
#
include
<SoftwareSerial.h>
SoftwareSerial
SoftSerial
(2, 3);
unsigned
char
buffer[64]; // buffer array for data receive over serial port
int
count = 0; // counter for buffer array
void
setup
()
{
SoftSerial.begin(9600); // the SoftSerial baud rate
Serial.begin(9600); // the Serial port of Arduino baud rate.
}
void
loop
()
{
// if date is coming from software serial port ==> data is coming from SoftSerial shield
if
(SoftSerial.available())
{
while
(SoftSerial.available()) // reading data into char array
{
buffer[count++] = SoftSerial.read(); // writing data into array
if
(count == 64)
break
;
}
Serial.write(buffer, count); // if no data transmission ends, write buffer to hardware serial port
clearBufferArray(); // call clearBufferArray function to clear the stored data from the array
count = 0; // set counter of while loop to zero
}
if
(Serial.available()) // if data is available on hardware serial port ==> data is coming from PC
or notebook
SoftSerial.write(Serial.read()); // write it to the SoftSerial shield
}
void
clearBufferArray
() // function to clear buffer array
{
// clear all index of array with command NULL
for
(
int
i=0; i<count; i++)
{
buffer[i]=NULL;
}
}
 Step 2. Open the Serial Monitor, the card information can be displayed as
shown below:

Wiegand Mode
(Jumper Set to the Right two Pins) You would need to select the jumper to "W" to enter
this mode. The Wiegand demo code for Seeeduino is designed to read Wiegand data in
interrupt mode.
In Wiegand Mode, output data is formatted with 26bits including 24bits card info and 2
bits parity.
bit
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
-
PE
D
-
-
E
0
-
-
D2[7..0]
D1[7..0]
 PE is even bit, PO is odd bit;
 E is the data bit which was involved in even, O is the data bit which was
involved in odd;
 DX[7..0] is the data bit which correspond to Mifare@ Standard & Light card
read only ID;
FAQs
Q1: How to convert the output to Card Number?
A1: Please follow below steps.
 Take ID: 0009776930 for example:

 Card Number ID: 0009776930 ------- Decimalism [Start Bit(00) + Card
Number(8 numbers)]
 Output: 0700952F229F ------------- Hex [[Start Bit(07h) + Card Number(8
numbers) + Checksum]
 The calculator for decimal and hex numbers is available online.
Q2: How to read tags continuously?
A2: The RFID reader can read tags continuously without any setting. Keep the tag 2.5-4
cm from the antenna, and the reader can read data continuously. And if the distance is
below 2.5cm, the reader reads data once if not moving tags away.
Resources
 [Demo] Grove - 125KHz RFID Reader Demo
 [PDF] Declaration of conformity
 [PDF] Test Report